Technical Field
The present invention relates to a light irradiator, an image reader and an image forming apparatus.
Description of the Related Art
Conventionally, an image reader such as scanners is equipped with a light irradiator irradiating light to a document surface to be read, located on a contact glass. The reading light irradiated by the light irradiator is reflected on the document surface and passes along an optical axis through a lens to form an image on an image reader such as a CCD based on the read document image.
As a light source for the light irradiator, e.g., a light emitting diode (LED) is used. Although having various good properties, the LED has insufficient absolute brightness of each of elements, such that it has been used for low-speed readers or compact equipment. Due to the recent progress in LED technologies, LED having higher brightness has been introduced which can be installed in a high-speed scanner requiring high document surface illuminance.